Firstly, apologies for any incorrect terminology - this is my first time trying to manipulate GIS data.
I have two files. The first is higher resolution (SRTM) topography data for a region of islands ...

Why does the top of a mountain appear bright on a SAR (radar) image.
I know that the peak of a mountain is subject to a layover effect, thus appearing closer on the radar image than the bottom part of ...

I am using QGIS and I have been faced with the problem of topographical maps. From searching online I could only find data for the United States. Google maps offers elevation contours, however I am ...

There is enough literature on the topographic correction of satellite images, but in what cases the non Lambertian methods are preferred (over Lampertian)? do we determine the appropriate method only ...

I'm wondering how to proceed if you want to calculate how a location on land will get direct sunshine at a given time on a given date (compared being in the shadow of the mountains)? The area is very ...

I am not too familiar with techniques, and was looking for ways to make a slope map for a given area. It ended with finding this site and posting the question.
We are in the process of zoning a new ...

SAGA GIS puts too many maxima points on plains and lakes. Why does it happen? Is there a way to avoid this? It's not really a big problem (the value is correct) except for the size of the SHP files in ...

Is there a way to create a relatively precise topographical map of a private land using GPS elevation data? As the land is a little bit over 100,000 square meters, the available regional topographical ...

I'm looking for an explanation of the least squares method used in the case of a correction of 3D point network.
We have reference points with known coordinates XYZ. We calculate intermediate points ...

I have a .asc file produced from a hydraulic model. The .asc file contains depth data of flood inundation. I want to superpose the depth asc file with my topography .asc file so I can identify where ...

I am trying to identify wetlands using different topographic indexes, e.g. TWI/CTI. And I would like to try out a method called FLAG (fuzzy landscape analysis in GIS), but I don't really understand ...

I have a project I'm working on where I need a QGIS multi-layer Topo Map go the Lorraine Region of France between Metz and Nancy as a starting point, but I don't know where to start. What I need is a ...

I'm looking for as detailed as possible topographic data for a certain area and have found information displayed by Google Maps to be far more detailed than what is provided by 7.5 minute maps (from ...

I have 8 terabytes of imagery that is in either lon/lat or UTM projection that I will be using for the basis of large scale topographic maps.
I have been studying the differences between Mercator and ...

I have a set of latitude, longitude, and elevation pairs (roughly a grid of such values, though it is not uniform), and I'd like to be able to plot an elevation map and perhaps also a shaded relief ...

I am a complete newbie to GIS so please excuse the simple question. I am looking for someone to point me in the right direction to get some answers and/or maybe provide links to where I can find some ...

I'm creating topo maps for my day hikes guides for national parks. I've already done one for Glacier National Park. When I was working on summits, I downloaded the data for Montana from GNIS and when ...

So I have been investigating the area around Jerome and Clarkdale Arizona using different USGS Topographic map sources of the same scale, but different time periods, and find that in some cases, the ...

I am trying to put together a safe routes map for a local lake. I have an old paper map that has a grid of various depths as points. I would like to draw contour lines through these points and create ...

How to measure topographic roughness irrespective of slope in ArcGIS? I have used many methods to generate roughness layers, including TRI, VRM (which is supposed to be less correlated with slope), ...

I am getting negative topographic index wetness values in SAGA GIS - anyone else every get this?
Not all negative values, but the minimum of the TWI range is negative for some steep watersheds we are ...

In the Topographic Index calculation, a is the upslope contributing area per unit contour length. Is the "unit contour length" calculated from examining the contour widths of the downslope cells that ...

For the Canadian National Topographic System, are there any index maps available that do not only show map numbers throughout the country, but also the most recently available update for each map?
As ...

I am a grad student involved with hydrological modeling. In the model I work on, we are calculating the Topographic Index (TI; without transmissivity - or set to 1) using Quinn's MFD algorithm. We do ...